Apparatus for exhausting electric lamps.



Patented Aug. 15, 1899.

W. F. SMITH.

APPARATUS FOR EXHAUSTING ELECTRIC LAMPS.

(Application filed Mar. 1, 1899.)

(No Model.)

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UNITED STATES PATENT OFFICE.

IVALTER E. SMITH, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE UNITED ELECTRIC IMPROVEMENT COMPANY, OF GLOUCESTER CITY, NEIV JERSEY.

APPARATUS FOR EXHAUSTING ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 630,997, dated August 15, 1899.

Application filed March 1, 1899. Serial No. 707,337. (No model.)

To all whom, it may concern: group is connected for a comparatively short Beitknown thatI, WVALTER F. SMITH, a citiinterval of time to the other terminal of the zen of the United States, residing at the city of source of current, so that each lamp of a Philadelphia, in the county of Philadelphia group is heated in succession by the passage and State of Pennsylvania, have invented certhrough its filament of the current. During 5 5 tain new and useful Improvements in Apparathis operation the exhaust or mercury pump tus for Exhausting Electric Lamps, of which is in operation, and since the lamps of the the following is a specification. groups are lighted or heated successively their The object of the invention is to provide temperature may be comparatively high, the

means for exhausting lamps which shall faoccluded gases may be rapidly expelled, and co cilitate the operation and insure excellent the exhaust apparatus can remove the gases results. so expelled, because the filaments are heated The invention comprises the improvements singly and successively. To this end I make hereinafter described and claimed. use of a switch 4., provided with a conducting The nature, characteristic features, and ring or collar 5, upon which bears a brush 6, scope of my invention will be more fully that is connected by way of the conductor 0 understood from the following description, with the source of current 3. Upon the cylintaken in connection with the accompanying drical surface of the switch l and insulated drawing, forming part hereof and in which is from it are contacts d d d (1 equal in num- 20 illustrated diagrammatically means embodyher to the number of lamps in each group and ing features of the invention. arranged as shown. Each of these contacts In the drawing groups of lamp-bulbs are is in electrical connection with the conductconnected with an exhaust connection 1, ing-collar 5 by way of a conductor. (Shown which in turn communicates with a suitable in dotted lines.) There are brushes arranged 2 5 vacuum-pump. Prior to my invention it has to touch the contacts d, &c., as the switch 4 been customary to connect groups of lampis shifted or rotated, and these brushes are bulbs in this manner and to simultaneously respectively provided with conductors e e e pass currents through all of their filaments 6 that communicate with one side of each while exhausting their bulbs. This is done lamp of the number. As shown, these con- 30 in order to expel by heat occluded gases from ductors are led to a block 7 and are there conthe filaments and to remove such gases from nected to terminals. The lamps a, 850., are the bulbs by the exhaust or mercury pump. connected with these terminals through suitlVhen this was done, the degree of heat to able fuses and by way of conductors f, f, j, which the filaments were subjected was necand f As the switch 4 is shifted the cir- 5 essarily limited, because otherwise the occuit is completed by way of the conductor 0, eluded gases would be driven off in volume brush 6, collar 5, and contacts d, &c., succesgreater than the vacuum-pump could take sively and singly by way 'of the conductors 6, care of. It was therefore customary to con- &c., and f, &c., with the lamps, so that the tinue to heat the filaments to a comparatively filaments of the latter are included in circuit 0 low degree of temperature for a considerable successively and one at a time, it being re- 0 length of time in order to expel occluded inembered that the other side of each lamp is gases from them as slowly as the vacuumalways in connection by way of the conducpump could take care of them. This entailed tors a, &c., and the common return 2 with the the consumption of considerable time and source of energy. If additional groups of 5 current and was not productive of the best lamps are employed, one side of each of them results. In my invention one side of each may be connected through a second block lamp of each groupis connected, as by conduclike the block 7 and illustrated at the righttors a a a a b b Z7 12 with a common return hand side of the sheet. In such case con- 2, that leads to one terminal of the source of ductors, as g g g g, are employed for con- 5o-current 3. The other side of cachlamp of each necting one side of the filament of each lamp Having thus described the nature and ob-; jects of my invention, What I claim as new,

and desire to secure by Letters Patent, is

Means for exhausting lamp-bulbs which comprise an exhaust connection com inunicating with a group of lamps, a source of current, and a switch and its circuit connections for successively cutting each lamp of the group into and out of circuit, substantially as described.

In testimony whereof I have hereunto signed my name.

WALTER F. SMITH. In presence of K. M. GILLIGAN, W. J. JACKSON. 

